"Human Behaviour" is a song by Icelandic recording artist Björk, released on 7 June 1993 by One Little Indian as the lead single from her debut studio album, Debut (1993). Produced by Björk's longtime collaborator Nellee Hooper, it reflects upon human nature and emotion from an animal's point of view. The song and video were inspired by British broadcaster and naturalist David Attenborough.

Critics praised "Human Behaviour" and called it a highlight of Debut. The song was an underground smash that peaked at number two on the US dance charts and reached number 36 on the UK Singles Chart. Its music video was directed by Michel Gondry and is the first time he and Björk collaborated. The video, like the song, is a story about the relation between humans and animals from the animal's point of view.

"After The Sugarcubes, I guess I had a mixture of liberation and fear. It had been obvious for a while in the band that I had different tastes than the rest. That's fair enough - there's no such thing as correct taste. I wrote the melody for "Human Behaviour" as a kid. A lot of the melodies on Debut I wrote as a teenager and put aside because I was in punk bands and they weren't punk. The lyric is almost like a child's point of view and the video that I did with Michel Gondry was based on childhood memories."

"Human Behaviour" was written by Nellee Hooper and Björk, and was produced by Hooper. The song was first written in 1988 when Björk was still the leading singer of the Sugarcubes; however, she decided not to release it with the band. "Human Behaviour" is a house song with a four-on-the-floor style, characteristic of the music in Debut. It features a "bouncing riff" sampled from Antônio Carlos Jobim, with "its syncopated beat consigned to a venerable orchestral instrument, the timpani."

The song was inspired by David Attenborough documentaries and by the relation between humans and animals. Björk explained to Rolling Stone, talking about the inspiration for the song: "'Human Behaviour' is an animal's point of view on humans. And the animals are definitely supposed to win in the end." On a recent question and answer session with fans on The Guardian website, Björk revealed more information about the writing of the song: "I wrote it I was referring to my childhood and probably talking about how I felt more comfortable on my own walking outside singing and stuff than hanging out with humans..." The song was also inspired by the riff from Ray Brown Orchestra's "Go Down Dying".

This is the first song on the "Isobel song cycle", a transcendental cycle in Björk's discography which goes from "Human Behaviour" to "Wanderlust" (2007). The B-side contained in the cassette edition of the single is the reggae-influenced "Atlantic", which was produced and written by Björk. Its lyrics talks about Björk's family: "My son has eight grandmothers and eight grandfathers and it's about the love and the complications of that".

The song was well received by music critics. In a retrospective review, Terry Nelson from Albumism said it is "brilliant", noting it as "a smart and quirky observation of us very strange humans as seen through the eyes of an animal." For AllMusic's Heather Pares, the song's "dramatic percussion provides a perfect showcase for her wide-ranging voice". Upon the single release, Larry Flick from Billboard magazine wrote that it "has her ripping that harsh and distinctive voice over a stark, militaristic dance beat. Alternative programmers surely will be captivated by the mystical combo of what eventually become mantra-like vocals and an insinuating bassline." Dave Sholin from the Gavin Report stated that here, Björk "gets off to an awesome start", adding that "it's time to introduce her to Top 40 audiences, who can't help but be blown away by the lyrical power and originality of this fresh entry." Caroline Sullivan from The Guardian said, "Its combination of smoky, jazz-club vibe and a sound that's often more a laryngeal reflex than a voice is addictively strange. In a year of female experimentalism, Bjork is out there on her own, and sounds just fine." In his weekly UK chart commentary, James Masterton felt it's "unfortunately a cacophonous mess".

Dave Simpson from Melody Maker named it Single of the Week, writing, "This is wonderful, the sort of spooky and unique experience I thought pop had abandoned long ago. [...] Mostly, though, it's The Voice that gives 'Human Behaviour' its near-intangible sparkle. I can't remember the last time I heard a voice so laden with intrigue (sexual tension, outrage, fear—they're all in there) or an avant-garde record that made such sense as pop." In their review of Debut, Music & Media commented, "This solo album succesfully [sic] marries eccentricity to accesibility [sic]. The musical-esque song 'Like Someone In Love' and the current single 'Human Behaviour' with those thundering timpani are prime examples of this." Martin Aston from Music Week gave it a score of four out of five, calling it a "sensual, subtle dance track that bodes well for the future." Simon Reynolds from the New York Times described the lyrics as a "parallel between the beastliness of humanity and the bestiality of nature. Johnny Dee from NME noted that "a swampy kettle drum jazz vibe circles around Bjork's rasping larynx, trying to find a melody but eventually settling for the search." Tom Graves from Rolling Stone wrote, "Only on the opening track, 'Human Behavior', do we get a glimmer of what the fuss was all about." Andrew Perry from Select said, "The Gang Starr-style swingin' jazz loop of 'Human Behaviour' asserts a gameplan of searching for landscapes in which to set Björk's familiar tonsillar acrobatics." Siân Pattenden from Smash Hits gave it two out of five.